This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-035245, filed Feb. 13, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a data-processing apparatus that comprises a cable for transmitting data at high speed between a plurality of units. More particularly, the invention relates to a notebook-type personal computer (hereinafter referred to as xe2x80x9cnotebook PCxe2x80x9d) that has signal lines for transmitting data to a liquid crystal display (hereinafter referred to as xe2x80x9cLCDxe2x80x9d) so that the LCD may display the data.
2. Description of the Related Art
In recent years, the clock frequency and the data-transmitting speed in the system buses have increased in notebook PCs. In notebook PCs, electromagnetic waves emanating from particular components are more intense than before. The electromagnetic waves adversely influence the other components of the notebook PC. The influence of electromagnetic waves is known as xe2x80x9celectro-magnetic interference,xe2x80x9d or xe2x80x9cEMI.xe2x80x9dMost notebook PCs incorporate means for protecting the components from EMI.
Most notebook PCs have a main unit and an LCD unit. The main unit has a keyboard on its upper surface. A hinge mechanism connects the LCD unit to the main unit, allowing the LCD unit to rotate. An LCD harness electrically connects the main unit and the LCD unit. The LCD harness is a bundle of lines and extends from the main unit into the LCD unit through the hinge mechanism. The LCD harness includes power lines, signal lines, and the like. The power lines can supply power to the LCD unit from the power-supply circuit provided in the main unit. The signal lines can supply data to the LCD unit from the display control circuit incorporated in the main unit.
A ferrite core, which is a hollow magnetic cylinder, wraps the LCD harness. The ferrite core minimizes not only the EMI caused by electromagnetic waves emanating from any component outside the LCD harness, but also the EMI caused by the electromagnetic waves emanating from, in particular, the signal lines included in the LCD harness
In the ferrite core, the signal lines and the power lines are bundled together. The electromagnetic waves emanating from the signal lines inevitably influence the power lines. Thus, the ferrite core cannot suppress the EMI (xe2x80x9cnoisexe2x80x9d) with as high an efficiency as is desired. The ferrite core is disadvantageous in another respect. It wraps the entire LCD harness, though it needs to wrap only the signal lines that generate electromagnetic waves. Thus, the ferrite core has an unnecessarily large inside diameter and inevitably occupies a large space.
The present invention has been made in view of the foregoing. Embodiments of the invention provide a data-processing apparatus that can efficiently inhibit EMI of electromagnetic waves.
A data-processing apparatus according to one embodiment of the invention comprises: a first unit comprising a power supply and a signal source; a second unit; a harness electrically connecting the first unit and the second unit and comprising a plurality of lines including power lines which supply power from the power supply to the second unit and signal lines which supply data from the signal source to the second unit; and a magnetic member wrapping only the signal lines.
A data-processing apparatus according to one embodiment of the invention comprises: a main unit comprising a power-supply circuit and a display control circuit; a display unit; a hinge mechanism which connects the display unit to the main unit, allowing the display unit to rotate; a harness electrically connecting the main unit and the display unit and comprising a plurality of lines including power lines which supply power from the power-supply circuit to the display unit and signal lines which supply data from the display control circuit to the display unit; and a magnetic member wrapping only the signal lines.
Additional advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.